While viewing the Hermann Grid,we see gray dots at the intersections of the lines that disappear when we look directly at an intersection.Most explanations of this phenomenon argue that it results from
A) fatigue of photoreceptors from looking at the bright lines.
B) the receptive field organization of ganglion cells.
C) color contrast.
D) color constancy.

Question

Quizplus · Accepted Answer

The receptive field organization of ganglion cells explains why we see gray dots at the intersections of the Hermann Grid that disappear when we look directly at an intersection. This phenomenon is due to lateral inhibition, in which light stimulating receptive fields inhibits the activity of neighboring cells. The receptive fields of ganglion cells in the retina are organized in an antagonistic center-surround manner, where cells respond to light in the center of their receptive field but are inhibited by light in the periphery. This inhibitory process is responsible for the gray dots at the intersections, which disappear when we look directly at those intersections because we are now stimulating the center of the receptive field, reducing the inhibitory effect.

While Viewing the Hermann Grid,we See Gray Dots at the Intersections